<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .a .b .c{

        }
        .c{

        }
    </style>
</head>
<body>
    <div id="app">
        <div class="name">Tom</div>
        <div class="age">18</div>
    </div>

    <script>
        let node = {
            tag:'div',
            id:'app',
            class:'',
            x:0,
            y:0,
            children:[
            {   
                tag:'div',
                id:'',
                class:'name',
                text:'Tom'
            },
            {   
                tag:'div',
                id:'',
                class:'age',
                text:'18'
            }
        ]
        }
    </script>
</body>
</html>